1. Field of the invention:
The present invention relates to a copying machine having a plurality of light sources for illuminating different kinds of originals.
2. Description of the prior art:
In copying machines using a photosensitive material, light is projected to expose the photosensitive material at an exposure position to form a latent image formed with selectively hardened pressure-rupturable capsules or an electrostatic latent image on the surface of the photosensitive material. In such copying machines, it is typical to scan the image of an original placed on an original table by means of an optical device and project the light reflected from the original onto the photosensitive material, but with the recent trend toward multifunctional performance, some copying machines are designed to be capable of using slidefilms as originals for copying on to paper. Conventional methods of copying slidefilms include the following.
(1) Light from a slidefilm is guided for projection to a stationary photosensitive member to expose the whole surface thereof for the formation of an image.
(2) Light from a slide projector is projected into a Fresnel lens mounted on an original table of a conventional scanning type copying machine, the projected light is then transmitted on to a photosensitive member by means of a scanning type optical device installed in the copying machine, and the photosensitive member is exposed to the light through a slit for the formation of an image.
However, the above-mentioned methods for copying slidefilms have had the following problems, respectively.
(1) Since the whole image forming area of the photosensitive member is exposed at one time, the photosensitive member is required to have a plane surface of the area that can hold the entire size of the formed image, which tends to increase the size of the image forming apparatus.
(2) Since the light is transmitted through a larger number of media to reach the photosensitive member than in a conventional copy process (copying an original placed on the original table), i.e. through a Fresnel lens and through lenses, mirrors, etc. for focusing the light from the slidefilm onto the Fresnel lens, luminous energy loss is very great. Also, the Fresnel lens, slide projector, etc. have to be disposed on or in the vicinity of the original table, which could cause scratching, breaking or other damage to the original table.